Research firm comScore is out with its new report measuring the state of the United States smartphone market for a three-month period ended September 30 and Apple’s iPhone grew its share to comprise a healthy 40.6 percent of the nation’s smartphone units. In other words, four out of each ten smartphones in the country were iPhones.

Samsung also gained share, LG stayed flat while HTC and Motorola both lost ground amid strong competition from Apple and Samsung devices. All told, iOS seems to be gaining ground overall, adding 0.7 percentage points to its share versus 0.2 percentage points for Android. The full reveal and charts can be found after the break…

Their data indicates that Apple grew from 39.9 percent share in June to 40.6 percent in September, a 0.7-percentage point gain. Samsung went from 23.7 percent in June to 24.9 percent share in September, a 1.2-percentage point increase.

It’s interesting that Samsung and Apple together grew by a combined 1.9 points, which is roughly the same as the 1.8 points loss by others so the two tech titans obviously continue to chip away market share from everyone else. comScore data includes only ten days of iPhone 5s/5c sales (the handsets went on sale on September 20).

As for total smartphone subscribers, the ubiquitous Android platform of course continues to lead with a 52 percent share, a modest 0.2-point gain from June. At the same time, Apple’s iOS (comScore counts only smartphones) is at 40.6 percent share while everyone else gets relegated to a single-digit share.

BlackBerry continues on a downward spiral and lost 0.6 points, now sitting at 3.8 percent. Microsoft grew slightly from 3.1 percent in June to 3.3 percent in September and Symbian stayed flat at 3.3 percent.

147.9 million Americans owned smartphones in September, up 4.5 percent since June.

Facebook was the top smartphone app with 74.3 percent share of the app audience, followed by Google Play (53.9 percent), Google Search (53.2 percent) and YouTube (49.6 percent). Pandora Radio cracked the top 5 for the first time with 49.3 percent reach.

iOS and Android together account for an astounding 92.4 percent market share, a new high.